Brucella spp

Question 1

Brucella spp. characteristics

Answer 1

• gram -
• non-motile
• short rods
• Slow growing
• fastidious organisms
• requiring CO2 & serum to grow
• Delicate & can be lost during the culturing process
• Most can be pathogenic
  
  • Facultative intracellular pathogens; can infiltrate cells & cause chronic infections

Question 2

Brucella abortus host

Answer 2

primarily in cattle, causing bovine brucellosis

Question 3

what can Brucella abortus cause

Answer 3

Causes necrotic placentitis leading to abortion in cattle
- may cause intermittent malaise & shedding in milk
- Leads to reduced fertility & a reduction in milk production

Question 4

what can Brucella abortus cause in M

Answer 4

In M, can colonise reproductive tract, leading to orchitis (inflammation of testicles) or epididymitis

Question 5

what can Brucella abortus cause in f

Answer 5

Can cause chronic disease with small granulomas in LN & joints in F

Question 6

Zoonotic potential of brucella abortus

Answer 6

• Humans can be exposed through aborted foetuses, foetal membranes (which are highly infectious), uterine discharges (which can excrete bacteria for 2-4 weeks), consumption of raw milk, during slaughter, or via veterinary care
• Laboratory personnel can also be affected due to spillage or lack of PPE

Question 7

Control of brucella abortus

Answer 7

• Treatment in cattle is ineffective, so test and slaughter is the only method to prevent its spread in a herd or country
• B. abortus has been eradicated in Australia through test and slaughter

Question 8

Brucella melitensis affected spp

Answer 8

Primarily in sheep & goats

Question 9

what can Brucella melitensis cause in sheep

Answer 9

Causes abortion in sheep and goats, and mastitis in goats

Question 10

Zoonotic potential of Brucella melitensis

Answer 10

• Causes Malta fever in humans
• It is the principal cause of human infection in places like India, West Africa, Iran, and Iraq, often through unpasteurised milk consumption or exposure from aborted foetuses and uterine discharges

Question 11

Brucella suis host spp

Answer 11

Primarily pigs, causing porcine brucellosis
- In feral pigs, it is commonly carried
- It is not present in domesticated livestock or pigs in Australia.

Question 12

What can Brucella suis cause

Answer 12

In sows, it causes abortions, stillbirth, neonatal mortality, and temporary sterility

Question 13

Shedding of brucella suis

Answer 13

Boars can excrete Brucella in high concentrations in semen without showing issues, though it can occasionally cause testicular abnormality

Question 14

Transmission of brucella suis

Answer 14

• Pigs acquire it by ingestion or through corpses
• Emerging as a disease in hunting dogs in Australia, particularly those exposed to raw feral pig meat or direct contact with wild pigs.
  
  • Dogs can then transmit it to other dogs
  • Some infected dogs may appear healthy but be carriers

Question 15

Zoonotic Potential & Human Infection of burcella suis

Answer 15

• It is a major zoonotic disease
• Can cause brucellosis in humans, especially feral pig hunters
• Humans can acquire it through direct contact with pig

Question 16

clinical signs in dogs brucella suis

Answer 16

if presenting with reproductive tract signs, enlarged testicles, back pain, or lameness, especially with a history of feral pig exposure, B. suis should be considered

Question 17

List ways dogs contract Brucella suis

Answer 17

Contact with raw feral pig meat
Direct contact with wild (feral) pigs
Dog-to-dog transmission

Question 18

Describe the ways of disease contraction in dogs brucella suis

Answer 18

• contact with raw feral pig meat: Dogs can acquire the infection by ingesting or being in contact with raw meat from feral pigs.
• Direct contact with wild (feral) pigs: Dogs can also become infected through direct interaction with wild or feral pigs.
• Dog-to-dog transmission: Once a dog is infected, it can then transmitB. suisto other dogs.

Question 19

Risk factors of brucella suis for dogs

Answer 19

• Reproductive tract signs.
• Enlarged testicles(as seen in images of affected dogs).
• Back pain.
• Lameness.
• Ahistory of feral pig exposure(e.g., hunting dogs).
• Exposure to another dog that could have been involved in feral pig hunting.

Question 20

Human brucellosis is characterised by:

Answer 20

• Chronic relapsing fever.
• Joint and muscle pain.
• Chills.
• Episodic weakness.
• Headaches.

Question 21

Complications of brucella suis in humans

Answer 21

Complications can includesuppurative arthritis,pericarditis, andmental depression. While themortality rate is low, the disease can make individuals very ill for extended periods, often without knowing the cause

Question 22

Major brucella spp for zoonotic potential

Answer 22

Brucella abortus
Brucella melitensis
Bruce’s suis
Brucella canis

Question 23

Describe Brucella abortus:

Answer 23

Primarily associated withbovine brucellosisin cattle, it causesundulant feverin humans.

Question 24

describe Brucella melitensis:

Answer 24

Primarily found insheep and goats, it is theprincipal cause of human infectionglobally, particularly in regions like India, West Africa, Iran, and Iraq. It causesMalta feverin humans.

Question 25

describe Brucella suis:

Answer 25

Carried by pigs (especially feral pigs), this species is a major zoonotic disease in humans, particularly affecting feral pig hunters.

Question 26

describe Brucella canis:

Answer 26

While mainly affecting dogs, it can potentially cause problems to humans.

Question 27

List transmission routes of brucella in humans

Answer 27

1.Direct or Indirect Contact with Infected Animals: 2. Consumption of Contaminated Food Products: 3. Occupational Exposure: 4. Accidental Exposure: 5. Animal-to-Human Transmission:

Question 28

describe human transmission of brucella Direct or Indirect Contact with Infected Animals:

Answer 28

- Exposure to aborted foetuses and foetal membranes, which are highly infectious. - Contact with uterine discharges, which can excrete bacteria in high numbers for 2-4 weeks after an animal aborts. - Direct contact with pigs (for *B. suis*). - Veterinary care of infected animals (cattle, sheep, goats, dogs).

Question 29

describe brucella Consumption of Contaminated Food Products:

Answer 29

Unpasteurised milk and raw meat from infected animals.

Question 30

Occupational Exposure brucella tranmsision

Answer 30

- Veterinarians, meat workers, and laboratory personnel are at a higher risk of exposure due to their handling of animals or cultures. - Exposure can occur through slaughter processes.

Question 31

Accidental Exposure brucella tranmsision

Answer 31

Vaccination accidents or laboratory accidents involving cultures or spillage.